The mechanical and electrical components of satellite communications equipment intended particularly for marine applications must be of a very high quality that will guarantee a smooth and continuous operating time of at least about two years before the event of a malfunction. It can be mentioned as an example that the mechanical gyros available do not provide information on very small changes occurring in the three-dimensional space. The mechanism of such gyros is encumbered with a large intrinsic inertia which makes it impossible to handle information quickly enough to compensate for the rapid but small changes to which the equipment can be subjected in marine environments.
Equipment of this kind includes control systems which receive input data from transmitters in positioning systems. This input data is updated against non-linearity and operation due to thermic influences in electronic systems among other things, by calibrating actively against a "true" signal, ie the signal that is received by an antenna and that has its origin from the target object, the satellite, concerned, whose elevation and azimuth are well-defined for those geostationary satellites that can constitute a reference for "true" calibration.
It is only possible to satisfy the required tracking accuracy of 0.1.degree., by using an efficient and highly effective tracking system which is fast enough to track continuously satellite transmitted signals and to register any deviations that might occur in the X:Y:Z-directions. Those products that are available commercially at present are associated with very high investment costs (in the order of about SEK 1,000,000:-). Furthermore, it is difficult to find technical solutions that would enable the cost to be reduced by manufacturing in large numbers.
The object of the present invention is to eliminate the aforesaid drawbacks of a technical and economic nature.
The novel and inventive feeder horn is based on the basic concept of producing a physical phase difference between incoming signals solely mechanically. The characteristic features of an inventive feeder horn are set forth in the following claims.